The Bulls Island Recreation Area is approximately 60 miles north of Philadelphia.

According to authorities, the tree fell on a tent occupied by a Bound Brook, Somerset County family that had been camping overnight at the site.

State Park Police say William Arias, 46, was struck by the tree and killed. His wife, Elcetia, 42, was extricated from the debris and was flown to a Trenton hospital. She is currently in guarded condition. Their children, a son, age 10 and daughter, age 12, and a 9-year-old cousin were not injured.

The fallen tree is said to be an adult Sycamore tree which stood about 75 feet tall and weighed “several thousand pounds”.

Officials say the tree passed the seasonal inspection earlier this year and what happened early Tuesday morning, no one could have foreseen.

“You can’t know that a healthy looking tree might have some problems underneath so you do your best,” Larry Ragonese of the state Department of Environmental Protection said.

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Preliminarily, officials say their investigation revealed that the tree had rotting roots about 8 to 10 inches underground.

“There was absolutely no sign of this rot. All of the rot was below the surface. There was nothing visible,” John Trontis, also of the state Department of Environmental Protection explained.

So authorities maintain what happened to the Arias family was a terrible, freak accident.

Authorities say while their investigation and clean up continue, they will keep six of the 44 family campsites closed to the public.